Hi. Sorry for the long post before. Long time Mac user and before my 16 Mackbook Pro, was using my 2007 Macbook Pro and 2007 era IMAC to record into Logic through a digital mixer. I've been recording on computers/mac and PC, since the 90s, so none of this stuff is new to me, and my stuff has been stable before the 16 MBP. My problems were complicated by the fact that the audio problems I've been having were ONLY on the Macbook Pro 16 running Catalina.(And Big Sur). I was lucky enough to have other computers and hardware to troubleshoot, but if I didn't have other equipment to rule things out, theres no way I would have been able to figure any of this out. It turns out that there were about 4-6 different contributing factors, some of which where Apple/OS related, and some were not. The bottom line is that the 16 MBPro didn't like the USB/Firewire soundcard Combo that was in my Digital mixer. (Full-size X32). A firmware update to the soundcard appeared to help resolve the issue, but then I started getting random dropouts. Random as in 1 dropout after 20 minutes of recording. Troubleshooted this for 2 weeks before I swapped out the sound card for a USB only card. (Got rid of the USB/Firewire combo card. (X-UF).
The USB/Firewire card was working fine with my older macs, including a newer Macbook Pro running Mohave (13 2017).
For some reason, the card, even after a firmware update, doesn't like either 64 bit drivers, or something else with the new MBPro. After swapping out the card, I've been unable to reproduce the problem, and am so happy the issue appears to be driver related with my soundcard. I guess the lesson here for people having issues with 16 MBPros and having audio issues is to budget for new hardware/sound cards, esp if they are older. The fact that I was not able to reproduce the problem with my older macs had me convinced the issue was with the Macbook Pro. It turns out some older soundcards may not work well with either Catalina or something else in the MBPro 16.